CN108102713B

CN108102713B - Processing method of catalytic diesel oil

Info

Publication number: CN108102713B
Application number: CN201611045476.2A
Authority: CN
Inventors: 王仲义; 崔哲; 彭冲; 刘昶; 吴子明; 孙士可
Original assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Priority date: 2016-11-24
Filing date: 2016-11-24
Publication date: 2020-09-11
Anticipated expiration: 2036-11-24
Also published as: CN108102713A

Abstract

The invention discloses a catalytic diesel oil processing method. Cutting a catalytic diesel raw material into a light component and a heavy component; carrying out hydrofining and hydro-upgrading reactions on the light components to obtain gasoline and diesel components; hydrofining and hydro-conversion are carried out on the heavy component to obtain a gasoline component and a diesel oil component; the gasoline product is obtained after the two parts of gasoline and the diesel oil component are mixed, and the diesel oil product is obtained after the two parts of diesel oil component are mixed. The invention can process different types of raw materials selectively and independently through reasonable separation and processing processes, thereby being capable of reasonably utilizing inferior catalytic cracking diesel to produce qualified gasoline and diesel products.

Description

Processing method of catalytic diesel oil

Technical Field

The invention relates to a processing method of catalytic diesel oil, in particular to a method for processing catalytic cracking diesel oil to produce high-quality gasoline and high-quality diesel oil.

Background

Catalytic cracking is the most important secondary process in the petroleum refining industry at present, and is also the core process for heavy oil lightening. With the increasing weight of global petroleum, the processing capacity of the FCC device is continuously improved, various heavy oils are used as raw materials, the main product gasoline with high octane number is obtained through catalytic cracking reaction, and simultaneously, a large amount of catalytic diesel oil with high sulfur, nitrogen and aromatic hydrocarbon contents, low cetane number or cetane index and extremely poor stability is generated. And the requirements of environmental protection laws and regulations are increasingly strict, and the indexes of diesel products are gradually improved, so that strict requirements are imposed on the sulfur content, the aromatic hydrocarbon content, the cetane index and the like in the diesel products. Therefore, while the yield of the poor diesel oil is reduced, a proper method needs to be found for processing the poor diesel oil so as to meet the requirements of product delivery of enterprises.

The catalytic hydrogenation technology has important significance for improving the processing depth of crude oil, reasonably utilizing petroleum resources, improving product quality, improving yield of light oil and reducing atmospheric pollution, particularly has more remarkable importance for catalytic hydrogenation under the condition that the weight of the current petroleum resources is changed and the quality is deteriorated, can improve the hydrogen-carbon ratio in fuel oil products, optimizes product quality and improves emission standard through proper hydrogenation, becomes an indispensable component in the field of petrochemical industry at present, and can be divided into hydrogenation treatment and hydrocracking in the main process.

The catalytic diesel oil has very bad properties, so the current treatment means is single, and in China, the means which can be relied on mainly comprises the combined processing of the catalytic diesel oil and hydrogenation technology, such as the hydrofining after mixing the catalytic diesel oil and the straight-run diesel oil, the hydrocracking after mixing the catalytic diesel oil and the straight-run wax oil and the conversion technology which is used for producing gasoline by independently cracking the catalytic diesel oil in recent years.

CN1955257A introduces a method for producing high-quality chemical raw materials in a large quantity, which mainly mixes poor-quality catalytic cracking diesel oil and hydrogenation raw materials in proportion, and then produces catalytic reforming raw materials and high-quality ethylene raw materials by steam cracking through controlling reaction conditions. Although the catalytic cracking poor diesel oil can be processed, the processing path of poor raw materials is increased and the poor raw materials are converted into high-quality products, the proportion of blended catalytic diesel oil is still limited to a certain extent, the amount of the processable catalytic diesel oil is small, and the consumption of hydrogen for processing the catalytic diesel oil under the high-pressure condition is large.

CN103773455A the invention discloses a combined hydrogenation process of animal and vegetable oil and catalytic diesel, which essentially treats catalytic diesel through hydrofining, and although catalytic diesel can be processed through proper raw material proportion, the amount of catalytic diesel which can be blended is very small due to the limit of diesel product indexes, and the problem of treating a large amount of catalytic diesel of a large catalytic oil refining enterprise can not be thoroughly solved.

CN104611029A discloses a catalytic cracking diesel oil hydro-conversion method, wherein catalytic diesel oil and hydrogen gas are mixed and then enter a hydrofining reactor for hydrofining reaction, and then enter a hydrocracking reactor for hydrocracking reaction. Although the high-octane gasoline can be produced by processing and catalyzing diesel components through a certain catalyst grading action, the chemical hydrogen consumption is relatively high, and the requirement on hydrogen resources of enterprises is relatively high.

Disclosure of Invention

Aiming at the problems in the prior art, the technical problem to be solved by the invention is to provide a hydrocracking process method for processing catalytic diesel oil raw materials. The method comprises the steps of analyzing conventional catalytic diesel oil, cutting and separating to separate tricyclic and higher aromatic heavy components (simultaneously containing a small amount of aromatic hydrocarbons with single-ring and double-ring long side chains) and aromatic light components, wherein the heavy components directly generate high-octane gasoline after reaction, and the light components generate high-cetane diesel oil after ring-opening continuous chain-breaking modification reaction. When the catalytic diesel raw material is treated, all components are independently processed, the pertinence is strong, a high-quality fuel oil product can be produced, and compared with other technologies, the catalytic diesel oil production method has the characteristics of low chemical hydrogen consumption and flexible product structure adjustment.

The invention provides a processing method of catalytic diesel oil, which comprises the following steps:

a) cutting and separating the catalytic diesel raw material to obtain a light component and a heavy component;

b) the light component obtained in the step a) is used as raw oil and enters a reactor containing hydrofining and hydro-upgrading catalysts for upgrading reaction, and the obtained reaction effluent is subjected to gas-liquid separation, fractionation and other processes to obtain upgraded gasoline, upgraded diesel oil and the like;

c) the heavy component obtained in the step a) is used as raw oil and enters a reactor containing hydrofining and hydro-conversion catalysts for conversion reaction, and the obtained reaction effluent is subjected to gas-liquid separation, fractionation and other processes to obtain converted gasoline, converted diesel oil and the like;

d) and (c) mixing the modified gasoline in the step b) with the converted gasoline in the step c) to obtain a qualified gasoline product. The modified diesel oil in the step b) is directly used as a diesel oil product, and the converted diesel oil in the step c) is mixed with the light component in the step a) after being circulated to carry out modification reaction.

The catalytic diesel of step a)The initial boiling point of the oil component is generally 160-240 ℃, preferably 180-220 ℃; the final distillation point is generally 320-420 ℃, and preferably 350-390 ℃; the aromatic hydrocarbon content is generally more than 50wt%, preferably 60wt% to 99 wt%; the density of the diesel fuel stock is generally 0.91g cm^-3Above, preferably 0.93 g/cm^-3The above.

The catalytic diesel oil raw material can be a catalytic cracking product obtained by processing any basic oil species, for example, the catalytic cracking product can be selected from catalytic diesel oil obtained by processing middle east crude oil, and specifically can be catalytic diesel oil components obtained by processing Iran crude oil, Sauter crude oil and the like.

The cutting separation described in step a) is a conventional distillation separation operation, which can adopt a flash separation or tray separation mode well known in the industry, and aims to separate the catalytic diesel into a light part and a heavy part. The cutting temperature of the light diesel oil and the heavy diesel oil is generally 290-350 ℃, and preferably 300-340 ℃. The light component is a liquid phase fraction below the division point, and the heavy component is a liquid phase fraction above the division point.

The hydrofining catalyst described in step b) and step c) comprises a support and a hydrogenation metal supported. Based on the weight of the catalyst, the catalyst generally comprises a metal component of group VIB of the periodic table of elements, such as tungsten and/or molybdenum, accounting for 10-35 percent of oxide, preferably 15-30 percent; group VIII metals such as nickel and/or cobalt, in terms of oxides, are in the range of 1% to 7%, preferably 1.5% to 6%. The carrier is inorganic refractory oxide, and is generally selected from at least one of alumina, amorphous silica-alumina, silica, titanium oxide and the like. The conventional hydrocracking pretreatment catalyst can be selected from various conventional commercial catalysts, such as hydrogenation refining catalysts developed by the Fushu petrochemical research institute (FRIPP), such as 3936, 3996, FF-16, FF-26, FF-36, UDS-6 and the like; it can also be prepared according to the common knowledge in the field, if necessary.

The gas-liquid separation and fractionation processes described in step b) and step c) are well known to those skilled in the art. The gas-liquid separation is a separation process of products in the hydro-upgrading process, and generally mainly comprises a high-pressure separator, a low-pressure separator, a circulating hydrogen system and the like; the fractionation process is a process for further refining a liquid-phase product of gas-liquid separation, and generally mainly comprises a stripping tower, a fractionating tower, a side-line tower and the like.

The hydro-upgrading catalyst in the step b) is a hydro-upgrading catalyst containing a molecular sieve, and refers to a common hydrocracking catalyst or a hydro-upgrading catalyst special for the invention. The hydrogenation modification catalyst comprises hydrogenation active metal, a molecular sieve component and an alumina carrier. The general hydrogenation modification catalyst is composed of hydrogenation active metal components such as W, Mo, Co, Ni and the like, a molecular sieve component, an alumina carrier and the like, and the content of the hydrogenation components is 5-40% by taking the weight of the catalyst as a reference. The hydro-upgrading catalyst specially used in the invention comprises WO by weight₃(or MoO)₃) 13-25 wt%, NiO (or CoO) 3-10 wt%, molecular sieve 5-40 wt% and alumina 5-50 wt%, wherein the molecular sieve can be Y-type molecular sieve. The hydrogenation modification catalyst mainly plays a role in carrying out a saturated ring-opening but continuous chain-breaking hydrogenation modification process on the bicyclic aromatic hydrocarbon. The conventional hydrogenation reforming catalyst can be selected from various commercial catalysts, such as 3963, FC-18 and other catalysts developed by FRIPP. Specific hydro-upgrading catalysts may also be prepared as desired according to common general knowledge in the art.

The hydroconversion catalyst of step c) is a hydroconversion catalyst comprising a molecular sieve, which is a catalyst specifically prepared according to the present process. The hydrogenation conversion catalyst comprises hydrogenation active metal, a molecular sieve component and an alumina carrier. The general hydrogenation conversion catalyst is composed of hydrogenation active metal components such as W, Mo, Co, Ni and the like, a molecular sieve component, an alumina carrier and the like. Hydroconversion catalysts, including by weight WO, specific for the present invention₃(or MoO)₃) 8-25 wt%, NiO (or CoO) 4-10 wt%, molecular sieve 20-50 wt% and alumina 20-50 wt%.

In the hydrogenation conversion catalyst recommended by the invention, the molecular sieve is a small-grain Y-type molecular sieve. The grain size of the small-grain Y-type molecular sieve is 400-600 nm, the infrared total acid is 0.2-0.5 mmol/g, and the proportion of the medium strong acid is more than 75% (mmol/g)^-1/mmol·g^-1) (ii) a The unit cell parameter is 2.430-2.436 nm; SiO 2₂/Al₂O₃The molar ratio is 10-70; the pore volume is 0.5-0.8 cm³The proportion of the secondary pore volume of 2-8 nm in the total pore volume is more than 55%. The Y-type molecular sieve has more accessible and exposed acid centers, is beneficial to the diffusion of hydrocarbon molecules, can improve the preferential conversion capacity of cyclic hydrocarbon, particularly tricyclic aromatic hydrocarbon, directionally saturates and breaks the aromatic ring in the tricyclic aromatic hydrocarbon, and produces the gasoline component with high octane number to the maximum extent. The hydroconversion catalyst containing the small-grain Y-shaped molecular sieve has the main function of performing selective reaction on tricyclic aromatic hydrocarbon in raw materials, and has poor selectivity on non-tricyclic two-ring and monocyclic aromatic hydrocarbon. The Y-type molecular sieve has a certain difference with the conventional Y-type molecular sieve, the grain size of the conventional modified molecular sieve is generally 800-1200 nm, and the pore volume is 0.35-0.50 cm³The proportion of the pore volume of the secondary pores of 2-8 nm to the total pore volume is generally 30-50%, and the proportion of the medium-strong acid is 50-70%. The hydroconversion catalyst may be used to prepare a satisfactory catalyst in accordance with common general knowledge in the art, as described above.

In the present invention, the technical term "medium strong acid" is conventional knowledge well known to those skilled in the art. In the field of catalyst preparation, NH is adopted as medium-strong acid₃TPD was analyzed, with 150 ℃ desorption defined as weak acid, 250 ℃ desorption defined as medium strong acid, and 400 ℃ desorption defined as strong acid.

In step c), the hydroconversion catalyst preferably adopts a catalyst grading filling scheme. The hydroconversion catalyst comprises at least two catalyst beds, and according to the contact sequence of the catalyst beds and reaction materials, the unit cell parameter of the Y-type molecular sieve in the catalyst of the upstream bed is generally 2.430-2.433 nm, the infrared total acid is 0.2-0.35 mmol/g, and SiO₂/Al₂O₃The molar ratio is 40-60; the unit cell parameter of the Y-type molecular sieve in the catalyst in the downstream bed layer is generally 2.433-2.436 nm, the infrared total acid is 0.35-0.5 mmol/g, and SiO₂/Al₂O₃The molar ratio is 20-30. Compared with the catalyst in the upstream bed layer, the proportion of 2-8 nm secondary pores in the catalyst in the downstream bed layer to the total pore volume is 5-20 percent lower, and the content of the Y-type molecular sieve is 5-20 percent higher. Wherein the requirements are metThe modification treatment process of the Y-type molecular sieve can be performed by using the conventional techniques in the art, for example, the Y-type molecular sieve can be treated by referring to the method described in CN 104588073A.

According to the difference between the unit cell parameters of the Y-type molecular sieve and the total infrared acid amount, the catalysts can be matched according to the difference of the activity. Therefore, the hydrogenation performance and the cracking performance of the catalyst can be more reasonably excessive along the flowing direction of reaction materials, the hydrogenation and cracking processes are more specifically carried out on reactants, particularly tricyclic complex aromatic hydrocarbons, the middle ring of the catalyst is subjected to saturation cracking, and the catalyst is further directionally converted into a gasoline component with a high octane number to the maximum extent, so that the content of polycyclic aromatic hydrocarbons in the product can be greatly reduced, and the selectivity of the hydrogenation conversion is further improved.

The catalyst filled by grading technology is first contacted with the heavy catalytic diesel oil component containing great amount of tricyclic aromatic hydrocarbon and proper amount of bicyclic aromatic hydrocarbon for reaction. Because the polarity of the tricyclic aromatic hydrocarbon is stronger, the adsorption capacity is stronger, and the cracking difficulty is not large, the upstream catalyst has slightly low molecular sieve content and higher secondary pore proportion, the acidity is moderate, and the tricyclic aromatic hydrocarbon can be effectively and directly converted into a high-octane gasoline component containing monocyclic aromatic hydrocarbon; the downstream catalyst has higher molecular sieve content and lower secondary pore ratio, has stronger acidity, has ideal conversion performance for the bicyclic aromatic hydrocarbon with higher conversion difficulty, and can further convert the bicyclic aromatic hydrocarbon into a high-octane gasoline component containing monocyclic aromatic hydrocarbon. Therefore, by adopting the catalyst grading scheme, most of the raw materials can be directly converted into target products according to the reaction difficulty of different components in the raw materials, and the selectivity is further improved.

The reaction conditions of the modification reaction in the step b) are as follows: the volume space velocity is 0.5-4.0 h^-1Preferably 0.8 to 2.5 hours^-1(ii) a The hydrogen partial pressure is 4-13 MPa, preferably 6-10 MPa; the volume ratio of the hydrogen to the oil at the inlet is 300: 1-800: 1, preferably 400: 1-700: 1; the reaction temperature is 340-410 ℃, preferably 360-400 ℃.

The reaction conditions of the hydroconversion reaction in the step c) are as follows:the airspeed is 0.5-4.0 h^-1Preferably 0.8 to 2.5 hours^-1The pressure is 4-13 MPa, preferably 6-10 MPa, the volume ratio of hydrogen to oil at the inlet is 300: 1-800: 1, preferably 400: 1-700: 1, and the reaction temperature is 360-430 ℃, preferably 380-420 ℃. According to the difference of the cutting point and the distribution of the aromatic hydrocarbon in the light and heavy components, the hydroconversion reaction needs to control a certain conversion rate which is larger than the cutting point according to the content of the tricyclic aromatic hydrocarbon in the raw material, and generally the mass conversion rate is controlled to be not higher than 70 percent, preferably not higher than 50 percent.

The gasoline product and the diesel oil product in the step d) are high-quality components which can enter a blending pool for blending finished oil.

Compared with the prior art, the catalytic diesel oil combined processing method has the following advantages:

1. the catalytic diesel oil with high aromatic hydrocarbon content is processed, the mixture of the tricyclic heavy aromatic hydrocarbon and the mixture of the non-tricyclic light aromatic hydrocarbon are respectively processed through a cutting process of light-heavy separation, the tricyclic aromatic hydrocarbon which is most suitable as a hydro-conversion raw material can be subjected to a conversion reaction, the preparation, grading and technological parameter control of a catalyst are matched, the high-octane gasoline component can be produced to the maximum extent, meanwhile, the unreacted two-ring and single-ring heavy components in the hydro-conversion process are subjected to a modification reaction together with the non-tricyclic light aromatic hydrocarbon, and the preparation and technological parameter control of the catalyst are matched, the light components can be subjected to a saturated ring opening and hydrogenation process, and the high-cetane diesel oil component can be produced to the maximum extent. The method can process different types of raw materials independently in a targeted manner through reasonable separation and processing processes, simplifies the complex petroleum refining process, and maximizes the processing suitability and pertinence of each component while considering the processing difficulty when processing poor-quality catalytic diesel oil, thereby having great advantages.

2. The method deeply couples the separation, the hydro-upgrading and the hydro-conversion in the process flow, and obtains ideal comprehensive processing effect on the basis of pertinently treating raw materials and improving the product quality. Although each unit has stronger independence in the description process, different units can be organically combined and shared in practical application, so that the method has the advantages of equipment saving, low operation cost and the like, and simultaneously, due to the improvement of a heat exchange system brought by combination, the energy consumption of the device is reduced to a certain extent, the investment is reduced, and the method has wide application prospect.

3. According to the method, a new hydroconversion catalyst with stronger pertinence is developed on the basis of the original catalytic diesel hydroconversion catalyst, and the method is also a great embodiment of technical progress, can provide more catalytic selection directions for enterprises, and brings more visual economic benefits. The small crystal grain molecular sieve used by the hydro-conversion catalyst has large specific surface, particularly obviously increased external surface area, sharply increased ratio of surface atomic number to volume atomic number, shortened pore passage and increased exposed pore openings, thereby having higher reaction activity and surface energy and showing obvious volume effect and surface effect. Specifically, the following aspects are provided: because the external surface area is increased, more active centers are exposed, the diffusion effect is effectively eliminated, the catalyst efficiency is fully exerted, and the reaction performance of macromolecules is improved; the surface energy is increased, so that the adsorption capacity of the molecular sieve is increased, the adsorption speed is accelerated, and the effective adsorption capacity of the molecular sieve is improved; the small-crystal molecular sieve has short pore passage and small in-crystal diffusion resistance, and the huge external surface area enables more orifices of the small-crystal molecular sieve to be exposed outside, so that the small-crystal molecular sieve is beneficial to the rapid in-and-out of reactant or product molecules, and can prevent or reduce the formation of carbon deposition caused by the accumulation of the product in the pore passage, thereby improving the turnover rate of the reaction and the service life of the molecular sieve; has uniform radial distribution of the skeleton components, thereby improving activity and selectivity; the method is more beneficial to the realization of the modification technology after the synthesis of the molecular sieve; for molecular sieve supported metal catalysts, the use of small crystallite molecular sieves is beneficial in increasing the effective loading of the metal component and improving the dispersion properties of the metal component. In addition, the proportion of secondary pores in the molecular sieve can be further increased through subsequent modification treatment, the pore structure of the molecular sieve is unblocked, macromolecule adsorption reaction and desorption are facilitated, the directional hydrogenation conversion capability of macromolecule heavy aromatics is greatly enhanced, and the saturation and cracking of the intermediate ring can enable high-octane gasoline components in the product to be more.

Drawings

FIG. 1 is a schematic flow diagram of the process of the present invention.

Detailed Description

The combined process of the present invention will be described in detail with reference to the accompanying drawings. Only the main description of the process flow is given in fig. 1, and some necessary equipment and vessels are also omitted from the schematic.

As shown in figure 1, the combined process flow for processing catalytic diesel oil of the invention is as follows: after a catalytic diesel raw material 1 enters a separator 2, a light component 3 is obtained at the upper part, a heavy component 8 is obtained at the lower part, the light component 3 is mixed with hydrogen 4 and then enters a hydro-upgrading reactor 5 to be in contact reaction with a catalyst, a reaction effluent 6 enters a separation and fractionation system 7, a gas phase 8' is discharged from the upper part, a modified gasoline 9 is obtained at the middle part, and a modified diesel 10 is obtained at the bottom; the heavy component 8 and hydrogen 11 are mixed and then enter a hydrogenation conversion reactor 12 to be in contact reaction with a hydrogenation conversion catalyst, a reaction effluent 13 enters a separation and fractionation system 14, a gas phase 15 is discharged from the upper part, conversion gasoline 16 is obtained from the middle part, and conversion diesel oil 17 obtained from the bottom part is mixed with the light component 3 for common reaction before being recycled to the reactor 5; the modified gasoline 9 is mixed with the converted gasoline 16 to obtain qualified gasoline 18.

The combined process of the present invention is further illustrated by the following specific examples.

Example 1

The technological process shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 300 ℃, and target products are high-quality gasoline and diesel oil. The catalysts used in the examples were a commercial catalyst FF-36 hydrotreating catalyst, a 3963 hydro-upgrading catalyst, and a hydroconversion catalyst a.

Example 2

The technological process shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is selected to be 300 ℃, and target products are high-quality gasoline and diesel oil. The catalysts used in this example were a commercial catalyst FF-36 hydrotreating catalyst, a 3963 hydro-upgrading catalyst, and the art-specific hydroconversion catalysts a and B.

Example 3

The technological process shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 310 ℃, and the target products are high-quality gasoline and diesel oil. The catalysts used in the examples were commercial catalysts FF-36 hydrotreating catalyst, 3963 hydro-upgrading catalyst, and hydroconversion catalysts a and B.

Comparative example 1

The technological process shown in figure 1 is adopted, catalytic diesel oil is selected as a raw material to carry out hydrogenation production, the cutting point of light and heavy components is 300 ℃, and target products are high-quality gasoline and diesel oil. The catalysts used in the comparative examples were a commercial catalyst FF-36 hydrotreating catalyst, a 3963 hydro-upgrading catalyst, and a conventional hydroconversion catalyst C.

Comparative example 2

Comparative example 2 is a conventional catalytic diesel hydroconversion process, catalytic diesel is selected as a raw material for hydrogenation production, and the target products are high-quality gasoline and common diesel. The catalysts used in the comparative examples were a commercial catalyst FF-36 hydrotreating catalyst and a conventional hydroconversion catalyst C.

The properties of the special and conventional hydroconversion catalysts are shown in Table 1, the properties of the raw oil are shown in Table 2, the operating conditions are shown in Table 3 and the following Table 3, and the properties of the main products are shown in Table 4.

TABLE 1 Main physicochemical Properties of catalysts tailored by this technology

Item	Hydroconversion catalyst A	Hydroconversion catalyst B	Hydroconversion catalyst C
				Chemical composition	Mo-Ni	Mo-Ni	Mo-Ni
Content of metal oxide, wt.%	20.7	19.0	17.1
				Physical Properties
Appearance shape	Cylindrical bar	Cylindrical bar	Cylindrical bar
				Crush strength, N/cm	≥150	≥150	≥150
Particle diameter, mm	1.1～1.3	1.1～1.3	1.1～1.3
				Wt% of Y-type molecular sieve	36	43	50
Property of Y-type molecular sieve
				Particle size, nm	550	450	990
Cell parameter, nm	2.431	2.436	2.438
				Proportion of secondary pores to total pore volume^*，v%	73.5	62.0	50.1
Total infrared acid, mmol/g	0.34	0.49	0.60
				Proportion of medium strong acid%	77	80	58

And the secondary pores with the diameter of 2-8 nm account for the total pore volume.

TABLE 2 raw oil Properties Table

TABLE 3 reaction conditions

TABLE 3 reaction conditions

As can be seen from the examples and comparative examples in tables 2 and 3, the present technology has a great advantage in hydrogen consumption for the production of gasoline by processing a large amount of catalytic diesel.

TABLE 4 Main Properties of the product

As can be seen from the above examples, the process of the present invention for treating catalytic diesel fuel raw material has certain advantages in the properties of the produced naphtha and diesel fuel products on the basis of large amount of processed catalytic diesel fuel and low hydrogen consumption compared with the comparative examples.

It can be seen from the above examples and comparative examples that the catalytic diesel raw material is cut and then processed respectively by the method, so that the inferior diesel components can be treated to the maximum extent, the diesel-steam ratio can be flexibly adjusted from the aspect of balance or saving of hydrogen resources according to the actual conditions of enterprises, and the production is carried out according to the change of market demands.

The separation, the hydro-upgrading and the hydro-conversion are combined in the process flow, and an ideal comprehensive processing effect is obtained on the basis of pertinently treating raw materials and improving the product quality. Although each unit has stronger independence in the description process, different units can be combined organically and shared in practical application, so that the method has the advantages of equipment saving, low operation cost and the like, and simultaneously, due to the improvement of a heat exchange system caused by combination, the energy consumption of the device is reduced to a certain extent, the investment is reduced, and the method has wide application prospect.

Claims

1. A processing method of catalytic diesel oil comprises the following steps:

a) cutting and separating the catalytic diesel raw material to obtain a light component and a heavy component; the cutting temperature of the light component and the heavy component is 290-350 ℃;

b) the light component obtained in the step a) is used as raw oil and enters a reactor containing hydrofining and hydro-upgrading catalysts for hydro-upgrading reaction, and the obtained reaction effluent is subjected to gas-liquid separation and fractionation processes to obtain upgraded gasoline and upgraded diesel oil;

c) the heavy component obtained in the step a) is used as raw oil and enters a reactor containing hydrofining and hydro-conversion catalysts for hydro-conversion reaction, and the obtained reaction effluent is subjected to gas-liquid separation and fractionation processes to obtain converted gasoline and converted diesel oil;

d) mixing the modified gasoline in the step b) with the converted gasoline in the step c) to obtain a qualified gasoline product; the modified diesel oil in the step b) is directly used as a diesel oil product, and the converted diesel oil in the step c) is mixed with the light component in the step a) after being circulated to carry out modification reaction;

the hydrogenation conversion catalyst in the step c) comprises hydrogenation active metal, a Y-type molecular sieve and an alumina carrier, wherein the particle size of the Y-type molecular sieve is 400-600 nm, the infrared total acid is 0.2-0.5 mmol/g, the proportion of medium-strong acid is more than 75%, and the unit cell parameter is 2.430-2.436 nm; the pore volume is 0.5-0.8 cm³The proportion of the 2-8 nm secondary pore volume to the total pore volume is more than 55%;

the hydroconversion catalyst comprises at least two catalyst beds, and according to the contact sequence with the reaction materials, compared with the catalyst in the upstream bed, the proportion of 2-8 nm secondary pores in the Y-type molecular sieve in the downstream bed catalyst to the total pore volume is lower by 5-20%, and the content of the Y-type molecular sieve is higher by 5-20%; the unit cell parameter of the Y-type molecular sieve in the upstream bed layer catalyst is 2.430-2.433 nm, and the infrared total acid is 0.2-0.35 mmol/g; the unit cell parameter of the Y-type molecular sieve in the catalyst in the downstream bed layer is 2.433-2.436 nm, and the infrared total acid is 0.35-0.5 mmol/g.

2. The process according to claim 1, wherein the catalytic diesel feedstock has a primary boiling point of 160 to 240 ℃, a final boiling point of 320 to 420 ℃, an aromatic content of 50wt% or more, and a density of 0.91 g-cm^-3The above.

3. The process according to claim 2, wherein the catalytic diesel feedstock has a primary boiling point of 180 to 220 ℃, an end point of 350 to 390 ℃, an aromatic content of 60 to 99wt%, and a density of 0.93 g-cm^-3The above.

4. The process of claim 1 wherein the light and heavy components are cut at a temperature of from 300 ℃ to 340 ℃.

5. The process of claim 1 wherein said hydro-upgrading catalyst comprises a hydrogenation-active metal, a molecular sieve component and an alumina support; the catalyst comprises WO by weight₃Or MoO₃13-25 wt%, NiO or CoO 3-10 wt%, Y-type molecular sieve 5-40 wt% and alumina 5-50 wt%.

6. The process of claim 1 wherein said hydroconversion catalyst comprises, by weight, WO₃Or MoO₃8-25 wt%, NiO or CoO 4-10 wt%, Y-type molecular sieve 20-50 wt% and alumina 20-50 wt%.

7. The process of claim 1 wherein said hydro-upgrading reaction of step b) is carried out under reaction conditions of: the volume airspeed is 0.5-4.0h^-1The hydrogen partial pressure is 4-13 MPa, the volume ratio of hydrogen to oil at the inlet is 300: 1-800: 1, and the reaction temperature is 340-410 ℃; the reaction conditions of the hydroconversion reaction in the step c) are as follows: the volume space velocity is 0.5-4.0 h^-1The hydrogen partial pressure is 4-13 MPa, the volume ratio of hydrogen to oil at the inlet is 300: 1-800: 1, and the reaction temperature is 360-430 ℃.

8. The process of claim 7 wherein said hydro-upgrading reaction of step b) is carried out under reaction conditions of: the volume space velocity is 0.5-4.0 h^-1The hydrogen partial pressure is 6-10 MPa, the volume ratio of hydrogen to oil at the inlet is 400: 1-700: 1, and the reaction temperature is 360-400 ℃; the reaction conditions of the hydroconversion reaction in the step c) are as follows: the volume space velocity is 0.8-2.5 h^-1The hydrogen partial pressure is 6-10 MPa, the volume ratio of hydrogen to oil at the inlet is 400: 1-700: 1, and the reaction temperature is 380-420 ℃.

9. The process of claim 1 wherein said hydroconversion controls the mass conversion of said feedstock above the cut point to not more than 70%.

10. The process of claim 1 wherein the upstream catalyst to downstream catalyst packing volume ratio is from 1:5 to 5: 1.